U.S. Pat. No. 6,189,556 to Blake, et al., incorporated herein in its entirety by this reference, discloses valves for distributing water to multiple “pop-up” cleaning heads embedded in floors and walls of pools. Although not especially relevant to the invention described herein, the valves of the Blake patent connect to return lines of water-filtration or circulation systems of swimming pools. As noted in the Blake patent, such systems conventionally may include a length of polyvinyl chloride (PVC) pipe extending from a filter that “receives pumped pool water from the high pressure outlet port of a conventional pool pump” which in turn “receives water from the main drain of the swimming pool.” See Blake, col. 5, 11. 31-34.
U.S. Pat. No. 6,041,453 to Barrow, et al., likewise incorporated herein in its entirety by this reference, describes debris skimmers designed for connection to swimming pool return lines. Although again not especially relevant to the present invention, the skimmers of the Barrow patent utilize flexible hose to extend from fittings of a return line. Such hoses connect to corresponding fittings in the undersides of the skimmers.
Neither the Blake patent nor the Barrow patent contemplates adapting connections to different sizes of return lines. This may present significant problems in many pools, as differing diameters of PVC (or other) pipe frequently are used by different builders and in different types of pools. Absent some means of adapting products to these differing-diameter lines, effective utilization of the products to facilitate cleaning of swimming pools likely will be impeded (if not impossible).
Polaris Pool Systems, Inc. markets a return line adaptor as Part No. 9-100-8003 (the “Polaris Adaptor”). Intended for use with its Polaris 360 pressure-side automatic pool cleaner, the Polaris Adaptor consists of an “expansion connector” with an internally-threaded portion and an elongated portion designed for insertion into a larger-diameter return line. The elongated portion includes multiple leaves arranged circularly and retained in position by an elastic sheath. After the elongated portion is inserted into the return line, the internally-threaded portion may be rotated clockwise. Doing so overcomes the bias of the elastic sheath and expands the diameter formed by the leaves until it matches that of the return line and thus is frictionally fitted therein. Rotating the threaded portion counterclockwise apparently releases the frictional fitting, as doing so decreases the diameter of the expandable leaves.